This invention relates to an apparatus for separating a plurality of immediately adjacent strands of metallic sheet severed from a continuous moving flexible metallic sheet, such as aluminum sheet.
In the production of aluminum products, it is commonplace to prepare a large mill coil of aluminum sheet. This large coil is then uncoiled and slit into a number of strands and the adjacent strands thus formed are re-coiled into a series of new coils. Typically about 2 to 6 slits are made in an aluminum sheet to produce a plurality of adjacent strands.
After slitting, it is necessary to introduce some separation between slit coils when they are rewound so that the edges do not interweave or butt each other to produce belled edges. Traditionally, separation is achieved with about a 20 ft. unsupported strand length between the slitter head and rewind, with tapered steel discs being forced between the strands to establish the necessary fan-out. Narrow strands offer little resistance to the lateral shift controlled by the discs, but resistance increases with width and a split becomes more difficult to separate. When the resistance to shift becomes greater than the yield stress of the slit material, the result is a ripple or other strip edge damage. Various mechanical devices have been tried over the years to separate split coils, but most systems have been expensive or bulky, have been sensitive to the production of edge ripple and have required considerable operator skill and time to adjust.
Strip "profile" is common to all rolled stock and manifests itself in a slightly thicker, e.g. 1 to 2% thicker, section in the central area than at the edges. Since profile is nearly always symmetrical, a centre split coil will produce two strands of equal length. However, as the number of slit strands increases, the different strand lengths resulting from the different profiles become apparent as lost tension during strand buildup on the re-coil.
Roll devices are known which include automatic centering means for belts and one such device is described in Lorig, U.S. Pat. No. 2,772,879, issued Dec. 4, 1956. That device includes a roll with radial separations to provide laminations. These are inclined radially towards the axis of the roll away from the transverse centre line thereof.
It is an object of the present invention to provide a roll device which is capable of laterally separating a plurality of strands slit from a continuously moving flexible metallic sheet.